The Effects of Selected Herbicides on Musk Thistle (Carduus nutans) Viable Achene Production

Chlorsulfuron, metsulfuron, clopyralid, 2,4-D, picloram, and dicamba plus 2,4-D were spring-applied to musk thistle in rosette, bolting, bud, and early flower growth stages. All treatments reduced viable achene production at all musk thistle growth stages at Mcgrew, NE, and Longmont, CO. However, differences occurred at Evergreen, CO, among treatments and growth stages. No achenes developed at Evergreen when herbicides were applied during the rosette stage with dicamba plus 2,4-D, picloram, or metsulfuron at 21 g ai/ha or during bolting with chlorsulfuron or metsulfuron at 21 g/ha. Chlorsulfuron applied during early bloom reduced viable achene production over 99% compared to untreated plants and the picloram treatment.

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Yellow Mignonette (Reseda lutea) in the United States

Weed Technology ◽

10.1017/s0890037x00023186 ◽

1995 ◽

Vol 9 (1) ◽

pp. 196-198

Author(s):

Jerry D. Harris ◽

Edward S. Davis ◽

David M. Wichman

Keyword(s):

The United States ◽

Growth Stages ◽

Perennial Weed ◽

Flower Growth ◽

Small Grains ◽

Noxious Weed ◽

Central Montana ◽

Early Flower ◽

The Mediterranean Basin ◽

Gravel Road

Yellow mignonette (Reseda lutea (L.) # RESLU) is a broadleaf perennial weed that is native to the Mediterranean Basin and Asia Minor. It has been spread around the world and is widely recognized in Australia as a troublesome noxious weed in croplands. It is a problem in cropland and pastures because of its high seed output, extensive reproductive root system, ability to thrive under disturbed conditions, and high nitrate levels. While nitrate levels of 2.5 to 3.1% have been detected in plants during the rosette to early flower growth stages, when yellow mignonette is most palatable, no livestock injury or deaths have been reported. Yellow mignonette was first reported in Montana in 1958 but was not recognized as a weed problem until 1990. Since 1988 it has invaded several hundred hectares of small grains and alfalfa (Medicago sativa L.)-grass pastures in Central Montana and is spreading rapidly along gravel road shoulders.

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Matching herbicide application rates with the environmental conditions and growth stages of nodding thistle (Carduus nutans) and hairy buttercup (Ranunculus sardous) in pastures

Weed Biology and Management ◽

10.1111/j.1445-6664.2008.00297.x ◽

2008 ◽

Vol 8 (3) ◽

pp. 209-214 ◽

Cited By ~ 3

Author(s):

HAN EERENS ◽

JUDY MELLSOP

Keyword(s):

Environmental Conditions ◽

Growth Stages ◽

Herbicide Application ◽

Carduus Nutans ◽

Application Rates

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Ragwort and nodding thistle control with novel 24d mixtures

New Zealand Plant Protection ◽

10.30843/nzpp.2008.61.6883 ◽

2008 ◽

Vol 61 ◽

pp. 127-133

Author(s):

T.K. James ◽

A. Rahman

Keyword(s):

New Zealand ◽

Field Experiments ◽

Field Trials ◽

Growth Stages ◽

Senecio Jacobaea ◽

Carduus Nutans ◽

Potted Plants ◽

Regulatory Pressure ◽

Application Rates ◽

Better Than

For 50 years 24D has been the predominant chemical used for weed control on New Zealand farms but there is regulatory pressure to reduce application rates Pot and field experiments investigated the efficacy of lower rates of 24D when used in combination with either chlorsulfuron or mesotrione for control of ragwort (Senecio jacobaea) and nodding thistle (Carduus nutans) Experiments on potted plants evaluated herbicide combinations at several growth stages from small rosettes to prebolting while field trials were on weeds at bolting Ragwort was well controlled by the halfrate of 24D plus either chlorsulfuron or mesotrione For nodding thistle mesotrione was a better additive In the field trials control of both ragwort and nodding thistle from the half rate of 24D plus either chlorsulfuron or mesotrione was equal to or significantly better than that from the fullrate of 24D alone However in some instances there was also significant pasture damage

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SEASONAL DYNAMICS OF THE SUNFLOWER STEM WEEVIL, CYLINDROCOPTURUS ADSPERSUS (LECONTE) (COLEOPTERA: CURCULIONIDAE), ON CULTIVATED SUNFLOWER IN THE NORTHERN GREAT PLAINS

The Canadian Entomologist ◽

10.4039/ent1191131-12 ◽

1987 ◽

Vol 119 (12) ◽

pp. 1131-1137 ◽

Cited By ~ 6

Author(s):

Laurence D. Charlet

Keyword(s):

South Dakota ◽

Great Plains ◽

Northern Great Plains ◽

Growth Stages ◽

Regression Equations ◽

Flower Bud ◽

Bud Growth ◽

Production Areas ◽

North And South ◽

Early Flower

AbstractThe sunflower stem weevil, Cylindrocopturus adspersus (LeConte), is a pest of cultivated sunflower in the major production areas of North and South Dakota, Minnesota, and Texas. Adults appeared in sunflower plots between 5 and 25 June in 1980–1985, when plants had 4–14 leaves. Oviposition began soon after adults were present and continued into late August. Peak densities of both eggs and adults occurred in mid-July. Larvae hatched between 6 and 11 July, when plants were in the early flower bud growth stages. Larvae fed in the sunflower stalk and moved to the stalk base or root crown to construct overwintering chambers. The seasonal patterns of the weevil’s life stages in 6 years were similar, but population densities varied. Regression equations were developed to predict larval numbers in stalks from number of adults to aid in making control decisions.

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Wheat Response to Simulated Drift of Glyphosate and Imazamox Applied at Two Growth Stages

Weed Technology ◽

10.1614/wt-04-273r.1 ◽

2006 ◽

Vol 20 (1) ◽

pp. 23-31 ◽

Cited By ~ 21

Author(s):

Zacharria A. Deeds ◽

Kassim Al-Khatib ◽

Dallas E. Peterson ◽

Phillip W. Stahlman

Keyword(s):

Field Experiments ◽

Yield Loss ◽

Yield Reduction ◽

Growth Stages ◽

Stages Of Growth ◽

Stage Of Development ◽

Herbicide Treatment ◽

Jointing Stage ◽

Early Flower ◽

Accurate Indicator

Field experiments were conducted at Hays and Manhattan, KS, in 2002 and 2003 to determine winter wheat response to simulated drift rates of glyphosate and imazamox. Glyphosate and imazamox at 1/100×, 1/33×, 1/10×, and 1/3× of usage rates of 840 g ae/ha glyphosate and 35 g/ha imzamox were applied individually to wheat in the early jointing or the early flower stages of growth. Wheat injury and yield loss increased as herbicide rate was increased, with minimal effect from either herbicide at the 1/100× rate, and nearly complete kill and yield loss of wheat from both herbicides applied at the 1/3× rate, regardless of growth stage at application. In general, wheat injury and yield reduction were greater from glyphosate than from imazamox. In addition, wheat injury and yield loss were greater from herbicide treatment at the jointing stage than at the flowering stage of development. Correlation analysis suggests that visual injury is an accurate indicator of yield reductions. Germination tests of harvested grain showed that the viability of the wheat seed was not reduced if plants survived the herbicide treatment and produced a harvestable seed.

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Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083874 ◽

1978 ◽

Vol 36 (2) ◽

pp. 600-601

Author(s):

Wiktor Djaczenko ◽

Carmen Calenda Cimmino

Keyword(s):

Nervous System ◽

Glial Cells ◽

Early Period ◽

Postembryonic Development ◽

Ruthenium Red ◽

The Body ◽

Tubifex Tubifex ◽

Growth Stages ◽

Cell Processes ◽

Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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Characterisation of multilayer materials using a position-sensitive atom probe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176253 ◽

1990 ◽

Vol 48 (4) ◽

pp. 624-625

Author(s):

RAD Mackenzie ◽

G D W Smith ◽

A. Cerezo ◽

J A Liddle ◽

CRM Grovenor ◽

...

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Spatial Information ◽

Chemical Vapour ◽

Atom Probe ◽

Organic Chemical ◽

Growth Stages ◽

Multiple Quantum ◽

Quartz Wool ◽

Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

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